U.S. patent application number 12/504221 was filed with the patent office on 2010-05-13 for method of manufacturing ink-jet head.
This patent application is currently assigned to SAMSUNG ELECTRO-MECHANICS CO., LTD.. Invention is credited to Jae-Woo Joung, Pil-Joong Kang, Sang-Jin Kim.
Application Number | 20100116783 12/504221 |
Document ID | / |
Family ID | 42164255 |
Filed Date | 2010-05-13 |
United States Patent
Application |
20100116783 |
Kind Code |
A1 |
Kim; Sang-Jin ; et
al. |
May 13, 2010 |
METHOD OF MANUFACTURING INK-JET HEAD
Abstract
A method of manufacturing an ink-jet head is disclosed. The
method in accordance with an embodiment of the present invention
includes: forming a dividing groove such that one surface of a
piezoelectric element is divided corresponding to the position of
the chamber; filling the dividing groove with a filler; bonding one
surface of the piezoelectric element to one surface of the ink-jet
head in which the chamber is formed; and polishing the other
surface of the piezoelectric element such that the filler is
exposed.
Inventors: |
Kim; Sang-Jin; (Seoul,
KR) ; Joung; Jae-Woo; (Suwon-si, KR) ; Kang;
Pil-Joong; (Jinju-si, KR) |
Correspondence
Address: |
MCDERMOTT WILL & EMERY LLP
600 13TH STREET, N.W.
WASHINGTON
DC
20005-3096
US
|
Assignee: |
SAMSUNG ELECTRO-MECHANICS CO.,
LTD.
|
Family ID: |
42164255 |
Appl. No.: |
12/504221 |
Filed: |
July 16, 2009 |
Current U.S.
Class: |
216/27 |
Current CPC
Class: |
B41J 2/1623 20130101;
B41J 2/1646 20130101; B41J 2/161 20130101; B41J 2/1626 20130101;
B41J 2/1632 20130101 |
Class at
Publication: |
216/27 |
International
Class: |
B44C 1/22 20060101
B44C001/22 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 10, 2008 |
KR |
10-2008-0111230 |
Claims
1. A method of manufacturing an ink-jet head comprising a plurality
of chambers accommodating ink, the method comprising: forming a
dividing groove such that one surface of a piezoelectric element is
divided corresponding to the position of the chambers; filling the
dividing groove with a filler; bonding one surface of the
piezoelectric element to one surface of the ink-jet head in which
the chambers are formed; and polishing the other surface of the
piezoelectric element such that the filler is exposed.
2. The method of claim 1, further comprising, before the bonding of
the surfaces: forming a fixing groove on one surface of the ink-jet
head such that the piezoelectric element is accommodated; and
inserting the piezoelectric element into the fixing groove.
3. The method of claim 2, wherein the forming of the fixing groove
is performed by etching one surface of the ink-jet head.
4. The method of claim 3, wherein the one surface of the ink-jet
head is made of a Silicon on Insulator (SOI) substrate, in which
silicon is bonded to both sides of an oxide layer.
5. The method of claim 1, further comprising removing the filler,
after the polishing.
6. The method of claim 5, wherein the removing of the filler is
performed by etching the filler.
7. The method of claim 1, further comprising forming a conductive
layer on one surface of the ink-jet head, before the bonding of the
surfaces.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of Korean Patent
Application No. 10-2008-0111230, filed with the Korean Intellectual
Property Office on Nov. 10, 2008, the disclosure of which is
incorporated herein by reference in its entirety.
BACKGROUND
[0002] 1. Technical Field The present invention relates to a method
of manufacturing an ink-jet head.
[0003] 2. Description of the Related Art
[0004] Ink-jet printers can perform printing by converting an
electrical signal to a physical force and ejecting ink droplets
through a nozzle. An ink-jet head can be manufactured by processing
various components such as a chamber, a restrictor, a nozzle, a
piezoelectronic element, etc., on corresponding layers and bonding
the layers with one another.
[0005] Recently, the ink-jet head is increasingly used not only in
the conventional graphic ink-jet industry for printing on paper or
fabric but also in the manufacture of electronic components, for
example, a printed substrate and an LCD panel, etc.
[0006] As a result, the ink-jet printing technology for an
electronic component that needs to discharge functional ink more
correctly and precisely than the conventional graphic printing
method requires functions that have not been required for the
conventional ink-jet head. While the basic requirements stipulate
the size and speed variation of discharged ink droplets, high
density nozzles and high-frequency characteristics are also
required for higher production.
[0007] In order to meet such requirements, the performance of a
piezoelectric element, which is an actuator of the ink-jet head,
needs to be improved urgently. In one of the methods of
manufacturing the actuator of the ink-jet head, a powder-like
piezoelectric element is mixed with a polymer binder at a certain
ratio on a pre-sintered ceramic vibration plate to have viscosity,
and then screen-printed, patterned and co-fired. In another method,
the piezoelectric element is sintered after the piezoelectric
element is patterned through the screen printing method, etc. on a
vibration plate made of a material having a melting point higher
than the sintering temperature of the piezoelectric element.
[0008] The actuator manufactured by the methods described above may
have a deteriorated performance due to, for example, a defective
pin hole inside the material and may be electrically disconnected
when forming an upper and lower electrodes.
[0009] Additionally, such methods make it difficult to process the
piezoelectric element functioning as an actuator to have a
thickness of less than 100 um and cause the outer shape of the
piezoelectric element to collapse. It is also difficult to align
the piezoelectric element when bonding the piezoelectric
element.
SUMMARY
[0010] The present invention provides a method of manufacturing an
actuator of an ink-jet head that can be made thinner and less
affected by crosstalk.
[0011] An aspect of the present invention features a method of
manufacturing an ink-jet head including a plurality of chambers
accommodating ink. The method in accordance with an embodiment of
the present invention can include: forming a dividing groove such
that one surface of a piezoelectric element is divided
corresponding to the position of the chambers; filling the dividing
groove with a filler; bonding one surface of the piezoelectric
element to one surface of the ink-jet head in which the chambers
are formed; and polishing the other surface of the piezoelectric
element such that the filler is exposed.
[0012] The method can also include, before the bonding of the
surfaces, forming a fixing groove on one surface of the ink-jet
head such that the piezoelectric element is accommodated, and
inserting the piezoelectric element into the fixing groove. The
fixing groove can be formed by etching one surface of the ink-jet
head. The one surface of the ink-jet head is made of a Silicon on
Insulator (SOI) substrate, in which silicon is bonded to both sides
of an oxide layer.
[0013] The method can also include removing the filler, after the
polishing. The the filler can be removed by etching the filler.
[0014] The method can also include forming a conductive layer on
one surface of the ink-jet head, before the bonding of the
surfaces.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a cross-sectional side view of an ink-jet head
according to an embodiment of the present invention.
[0016] FIG. 2 is a cross-sectional front view of an ink-jet head
according to an embodiment of the present invention.
[0017] FIG. 3 is a flowchart showing a method of manufacturing an
ink-jet head according to an embodiment of the present
invention.
[0018] FIGS. 4 through 11 are cross-sectional views showing a part
of an ink-jet head according to an embodiment of the present
invention.
DETAILED DESCRIPTION
[0019] Some of the characteristics and advantages of the present
invention will become apparent through the following drawings and
detailed description.
[0020] Hereinafter, a certain embodiment of a method of
manufacturing an ink-jet head in accordance with the present
invention will be described in detail with reference to the
accompanying drawings. In description with reference to the
accompanying drawings, the same reference numerals will be assigned
to the same or corresponding elements, and repetitive descriptions
thereof will be omitted.
[0021] FIG. 1 is a cross-sectional side view of an ink-jet head 100
according to an embodiment of the present invention. As shown in
FIG. 1, the ink-jet head 100 can include a reservoir 111, a
restrictor 113, a chamber 114, a membrane 115 and a nozzle 116.
[0022] The reservoir 111 accommodates ink and provides the ink to
the chamber 114 through the restrictor 113, which will be described
below. The reservoir 111 can be supplied with ink from the outside
of the ink-jet head 100 through an inlet port 112. The inlet port
112 and the chamber 114 can be formed in a third plate 30. The
reservoir 111 can be formed in a second plate 20.
[0023] The restrictor 113 links the reservoir 111 with the chamber
114, which will be described below, and is able to function as a
channel for supplying the ink from the reservoir 111 to the chamber
114. The restrictor 113 and the reservoir 111 can be formed in the
second plate 20.
[0024] The restrictor 113 is formed to have a smaller cross-section
than the reservoir 111. When pressure is applied to the chamber 114
by a piezoelectric element 190, which will be described below, the
restrictor 113 can control the flow of the ink that is supplied
from the reservoir 111 to the chamber 114.
[0025] One side of the chamber 114 is connected with the restrictor
113, and the other side of the chamber 114 is connected with the
nozzle 116. The chamber 114 is formed inside the ink-jet head 100
to accommodate the ink, and one side is covered with the membrane
115.
[0026] FIG. 2 is a cross-sectional front view of the ink-jet head
100 according to an embodiment of the present invention. As shown
in FIG. 2, a plurality of ink-jet heads 100 can be formed
lengthwise inside the ink-jet head 100.
[0027] Accordingly, the reservoir 111 described above can be
extended in the lengthwise direction ro form a plurality of
reservoirs, and Thus the restrictor 113 can be formed between each
reservoir 111 and each chamber 114.
[0028] The nozzle 116 is coupled to the other side of each chamber
114 and can provide a path through which the ink accommodated in
the chamber 114 is discharged outside the ink-jet head 100. The
nozzle 116 can be formed on a first plate 10.
[0029] An actuator 190 can be coupled to one side of the ink-jet
head 100, that is, an upper surface of the membrane 115, which
corresponds to the position of the chamber 114. The actuator 190
generates vibration and transfers the vibration to the chamber 114
through the membrane 115, providing pressure to the chamber 114.
The membrane 115 can be formed on a fourth plate 40.
[0030] An upper electrode (not shown) and a lower electrode 600 can
be coupled to one side of the ink-jet head 100 in order to supply
voltage to the piezoelectric element 190.
[0031] The ink-jet head 100 including the nozzle 116, the chamber
114, the restrictor 113 and the reservoir 114 described above can
be formed by laminating the first plate 10, the second plate 20,
the third plate 30 and the fourth plate 40, each of which has its
own structure. The first plate 10, the second plate 20, the third
plate 30 and the fourth plate 40 can be made of a silicon
substrate. Hereinafter, a method for manufacturing the ink-jet head
100 according to an embodiment of the present invention will be
described.
[0032] The method of manufacturing the ink-jet head 100 according
to an embodiment of the present invention includes forming a fixing
groove 500 by etching one surface of the ink-jet head 100 such that
a piezoelectric element 700 can be accommodated (S100), forming a
conductive layer 600 on one surface of the ink-jet head 100 (S200),
forming a dividing groove 710 such that one surface of the
piezoelectric element 700 is divided corresponding to the position
of the chamber 114 (S300), filling the dividing groove 710 with a
filler 712 (S400), inserting the piezoelectric element 700 into the
fixing groove (S500), bonding one surface of the piezoelectric
element 700 to one surface of the ink-jet head 100 in which the
chamber 114 is formed (S600), polishing the other surface of the
piezoelectric element 700 such that the filler 712 is exposed
(S700) and etching and removing the filler (S800). Since the method
enables the actuator 190 of the ink-jet head 100 to become thinner,
the driving voltage of the ink-jet head 100 can be reduced and a
frequency characteristic can be improved. In addition, since the
ink-jet head 1000 having the actuator 190 is separated for each
cell, it is possible to reduce the crosstalk and improve the
discharge characteristic of the ink-jet head 100.
[0033] FIGS. 4 through 11 are cross-sectional views showing a part
of the ink-jet head 100 according to an embodiment of the present
invention. It shall be understood that the first plate 10 and the
second plate 20 are omitted in FIGS. 4 through 11 for description
of the present embodiment.
[0034] As shown in FIG. 4, in order to form the piezoelectric
element 700, which is the actuator 190, the fourth plate 40 of the
ink-jet head 100 can be made of an SOI substrate. The SOI substrate
is manufactured by bonding silicon to both sides of an oxide layer
45 made of SiO.sub.2.
[0035] The oxide layer 45 can be used as an etching stop layer,
which can control the degree of etching during the etching and
forming of the fixing groove 500, which will be described below.
Therefore, the oxide layer 45 can be spaced by as much as the
thickness of the membrane 115 from the lower surface of the SOI
substrate.
[0036] As shown in FIG. 5, the fixing groove 500 is first formed by
etching one surface of the ink-jet head 100 such that the
piezoelectric element is accommodated (S100). The fixing groove 50
can be a space for inserting the piezoelectric element 700. The
piezoelectric element 700, which is inserted into the fixing groove
500, can easily maintain a certain positional relation with the
ink-jet head 100.
[0037] Therefore, in the polishing of one surface of the ink-jet
head 100, reliable polishing becomes possible to improve the
polishing quality. Furthermore, since the polishing makes it easier
to control the polishing thickness of the piezoelectric element
700, it is possible to make the actuator 190 thinner.
[0038] Since the fourth plate 40 is made of an SOI substrate on
which the etching stop layer made of the oxide layer 45 is
disposed, a uniform etched-surface can be obtained even for the
etching stop layer by etching the fourth plate 40.
[0039] The membrane 115 is formed in an area of the fourth plate 40
corresponding to the position of the chamber 114 and remaining
unetched. Therefore, the membrane 115 having a uniform thickness
can be obtained by using the SOI substrate and there can be a
constant distance between the actuator 190 and the chamber 114. As
a result, the actuator 119 can be better aligned.
[0040] Next, as shown in FIG. 6, a conductive layer 600 is formed
on one surface of the ink-jet head 100 (S200). The one surface of
the ink-jet head 100 can be one surface of the fourth plate 40 in
which the fixing groove 500 is formed. The conductive layer 600 can
be formed by, for example, sputtering on one surface of the fourth
plate 40. The conductive layer 600 is formed for electrically
connecting to the actuator 190, and can be a lower electrode, which
is used as a common electrode.
[0041] As shown in FIG. 7, the dividing groove 710 is formed such
that one surface of the piezoelectric element 700 is divided
corresponding to the position of the chamber 114 (S300). The
piezoelectric element 700 can have a sintered bulk shape so as to
have a certain shape.
[0042] The use of the bulk shaped piezoelectric element 700 in the
method of manufacturing the inkjet head 100 according to an
embodiment of the present invention can prevent the performance
deterioration caused by the defect of a pin hole, etc., inside the
piezoelectric element 700 during the process of performing the
patterning and sintering of the piezoelectric element 700.
[0043] One surface of the piezoelectric element 700 can be inserted
into the fixing groove 500 to face the membrane 115. The dividing
groove 710 can be formed to divide the piezoelectric element 700 in
correspondence with the position of the chamber 114. The dividing
groove 710 can be variable types according to the position and
shape of the chamber 114.
[0044] The dividing groove 710 has a depth that is greater than the
thickness of the actuator 190 to be formed so as to separate
adjacent actuators 190 from one another. The dividing groove 710
can be formed by a dicing process of mechanically cutting the one
surface of the piezoelectric element 700.
[0045] As shown in FIG. 8, the dividing groove 710 is filled with a
filler 712 (S400). The filler 712 can prevent impurity from being
inserted into the dividing groove 710 during the manufacturing of
the ink-jet head 100. Particularly, when the piezoelectric element
700 is bonded to the dividing groove 710, the filler 712 can
prevent an adhesive, which is interposed between the piezoelectric
element 700 and the dividing groove 710, from being filled in the
dividing groove 710.
[0046] The filler 712 can be in the form of powder and can be mixed
with a binder and coated on one surface of the piezoelectric
element 700 to fill the dividing groove 710. Then, the filler 712
that remains on one surface of the piezoelectric element 700
without being filled is removed. Then, the filler 712 filled in the
dividing groove 710 is hardened. The filler 712 can be made of a
material such as polymer.
[0047] As shown in FIG. 9, the piezoelectric element 700 is
inserted into the fixing groove 500 (S500) such that one surface of
the piezoelectric element 700, in which the dividing groove 710 is
formed, faces the basal surface of the fixing groove 500.
[0048] Next, one surface of the piezoelectric element 700 is bonded
to the one surface of the ink-jet head 100, in which the chamber
114 is formed (S600). The one surface of the ink-jet head 100 is
made of the fourth plate 40. As a result, the piezoelectric element
700 can be bonded to the fourth plate 40. The piezoelectric element
700 can be bonded to the fourth plate 40 by using an adhesive. In
this case, a step can be added to coat the adhesive on the fixing
groove 500 before the described piezoelectric element 700 is
inserted into the fixing groove 500.
[0049] As shown in FIG. 10, the other surface of the piezoelectric
element 700 is polished such that the filler 712 is exposed (S700).
Since the dividing groove 710 is formed in one surface of the
piezoelectric element 700 and the dividing groove 710 is filled
with the filler 712, the actuator 190 can be divided by polishing
the other surface of the piezoelectric element 700 such that the
filler 712 is exposed.
[0050] The coating of the other surface of the piezoelectric
element 700 can be performed on the entire one surface of the
ink-jet head 100, in which the fixing groove 500 is formed. Since
the piezoelectric element 700 has been inserted into the fixing
groove 500, it is possible to easily maintain the alignment of the
piezoelectric element 700 during the polishing process.
Additionally, the outer shape of the piezoelectric element 700
inserted into the fixing groove 500 can be prevented from being
collapsed during the polishing process, thereby preventing the
performance deterioration of the actuator 190.
[0051] In addition, the actuator 190 can be formed by polishing and
dividing the bulk shaped piezoelectric element 700. By doing this,
it is easier to control the thickness of the actuator 190 and make
the actuator 190 thinner.
[0052] As shown in FIG. 11, the filler 712 is etched off and
removed (S800). An etching solution corresponding to the filler 712
is coated on one surface of the ink-jet head 100 to perform the
etching of the filler 712. When the filler 712 between the
actuators 190 is removed, the actuators 190 are physically divided
from one another. Thus, it is possible to prevent any crosstalk
caused by the operation of an adjacent actuator.
[0053] Meanwhile, when a material having an excellent damping
performance is used as the filler 712, the filler 712 can absorb
the vibration of the adjacent actuator 190 and reduce the
crosstalk. In this case, the removing of the filler 712 can be
omitted, thereby remaining the filler 712 between the actuators 190
and allowing the filler 712 function as a damper.
[0054] While the present invention has been described with
reference to a particular embodiment, it shall be understood by
those skilled in the art that various changes and modification in
forms and details can be made without departing from the spirit and
scope of the present invention as defined by the appended
claims.
* * * * *